Tube expander



Nov. 4 1924. 1,514,099

A. a. PRING TUBE EXPANDER Fi led Jan. 24 .1921

8i l5 l I gwuen roz Arthur B. Prng Patented Nov. 4, 1924.

NWED- STATES 1,514,099 mear orrlcs.

ARTHUR B. rnnvdornonr neroiv, vvns r ,vrnerivre.

i TUBE nxreivnnn.

Application filed January 24, 1921; Serial No. 439525.

a self-centering tool, which, owing to the shape of the expanding rollers employed, will not cut the tube at the point where the expansion takes place.

A further object of the invention is to construct a tool of this nature which will be comparatively cheap to manufacture and highly efiicient in its operation.

lVith these and other objects in view as will be more specifically pointed out in the following description, reference will be had to the accompanying drawing forming apart of this specification and wherein like reference characters designate corresponding parts throughout the several views, in which Fig. 1 is a view in vertical section taken through the longitudinal axis of the tube and the tube expanding tool,

Fig. 2 is a transverse vertical sectional view taken through line 22 of Fig. 1,

Fig. 3 is an end view in elevation of the outer cage section,

Fig. 4 is a transverse vertical sectional view taken on line 4-4 of Fig. 1,

Fig. 5 is a perspective view of one of the expanding rolls, and

Fig. 6 is a vertical sectional detail view of a fragment of the outer cage section.

Referring to the drawing, reference numeral 1 designates the tube, such as a boiler tube, to be expanded for tight fit within the tube sheet 2. The expanding tool is composed of a cage made up of two tubular sections 3 and 4. The outer end of the section 4 is formed with a rib 5 which fits within an annular groove 6 to take the strain oil.

the screws 7 which secure the sections 3 and 4 together. Obviously, instead of these screws or other separate fastening means, the two sections 3 and 4 may be welded togather, since the cage is only made in two sections to facilitate manufacture, particularly the shaping of the pockets 8 which receive the expanding rollers. In the production of the cage, each section 3 and 4 is these parts. 9, 10,I11,:and

drilled on the centers marked 00 in -F'ig'. 3,

thereby producing the said pockets 8 with their overhanging walls 9, shouldered end wall portions 10, inclined'bearing surfaces 11, and end bearing wallportions 12. Then, because the expanding rollers must have rad al movementto fit v'arious sizes of tubes, :12 arcut inwardly toward the center of the bore '14 of the cage,

3 but on lines parallel with the radius thereof. Within these pockets 8 are arranged the, ex-' panding rollers 15,;andthese are substantially barrel shape, having tapered end portions 15" and 15" gradually merging into the central portion which throughout the greater portion of the length of the roll is substantially constant. These rollers, which are preferably three in number, are inserted through the bore of the cage and then moved radiall into their respective pockets, and confined therein by the axial tapered core 16. The outer end of the cage member 4 is formed with a shoulder 17 and unthreaded reduced portion 18 upon which is swiveled or journaled a bearing-cup 19 secured roa tatably by a thrust bearing nut 20 threaded on the extreme end of the cage section 4 and provided with ball bearings 21 which are in engagement with bearing cup 19.

Obviously, by elongating the cage section 4 between the rollers 15 and the cup 19, the tool may be used to flange tubes set in headers and the cup thereby permitted to bear on the outer header sheet and the rollers to work adjacent the inner h'eader or tube sheet. a

In operation, the rollers are entered through the bore of the cage and moved radially outward into their respective pockets and the tapered expanding and operating coreinserted axially of the cage. The cage is then moved endways into the tube to be expanded and because of the tapered portions 15, the rollers will enter of themselves and the operator will not have to reach in and assist with his hands the entry of the rollers into the tube as is customary with square ended rollers. The rollers, having been entered into the boiler tube, and the cup 19 bearing against the tube or header sheet, the operator then rotates the expanding core 16 to rotate the rollers 15 while expanding them. The limit of expansion is when the rollers bear against the bearing surface 11 as illustrated in Fig. 1.

The thrust, which, is considerable,is amply borneby, the ball thrust nut 20? and without materially affecting the ease of operation.

It Will be observed that because of the gradual enlargement of the rollers, the expansion takes place gradually and also,that,

like. The tapering of" the front ends'ot the rollersis=to;facilitate entry of the same into the tube 1 and expansion of. the tube Without cutting as already stated, Whilethe taperingof therear ends of the rollers istozfacilitatethe entry of the expanding pin or; core 1 6 between the: rollers, Obviously, any 9 proved,means, may beemployed for locking the thrust bearing nut.

What I claim and desire to secure by Letters Patent is A tube expander comprising a cage formed of. mating sections With interengaging tongue and groove connections and having av reduced, threaded end defining an external shoulder, expander rollers arranged in said cage, a cup shaped bearing member angular in cross sectionl and: having its bottom portion; rotatable onsaid cage and abutting said shoulder, an adjustable bearing member threaded onrthereduced end of the cage and arranged outwardly of? the first mentioned bearingsm-ember, and friction reducing devices arranged intermediatethe first and second mentionedz bearing members.

In testimony whereof I have hereunto set myhand.

. B} PRING. 

